While most other hormones are determined accurately and fairly readily by radioimmunoassay (RIA) the catecholamines and their metaoblites have eluded this technique to date. The proposed research should result in effective RIA systems or plasma metanephrine and normetanephrine. The chemistry which will be employed to develop these two assays will afford us an insight into pottential approaches for the developemnt of similar techniques for dopamine, norepinphrine and epinephrine. Metanephrine and normetanephrine are not immunogenic per se; the chemistry to conjugate them as haptens onto suitable proteins via succinoylation at the 4 OH position is outlined. Rabbits and/or goats will be used to produce antisera to the conjugates the standard immunological techniques will then be used to assess the possibility of using these antisera for practical RIA of plasma and urinary metanephrine and normetanephrine levels. A preliminary survey of the potential of using similar chemistry for the development of RIA of the catecholamines will be undertaken.